Split bushing



Jan. 19, 1965 R. BLEICHER 3,166,359

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United States Patent 3,166,359 SI'LiT BUSHING Robert L. Bleieher, Dayton, Ohio, assignor to Dayton Perforators, Inc, Dayton, Ghio, a corporation of Ghio Filed Dec. 21, 1961, Ser. No. 161,192 7 Claims. (Cl. 308-3) This invention relates to guide devices and more particularly to split guide units in the nature of bushings or dies.

A split guide unit is generally more economical to fabricate and install than an integral guide since the shape of the internal guide opening can be ground. However, it has a definite drawback in use. Its segments tend to separate under conventionally applied loads, irrespective of whether the unit is press or shrunk fit. Those versed in the art are fully aware of the operating difiiculties occasioned by a split unit which breathes or opens at planes of separation between various of its segments. The slightest shifting of the segments can cause damage of materials or elements on which they function, rendering them dimensionally inaccurate and in some instances causing malfunction.

The present invention provides improvements in split guide units which not only facilitate their application in a simple yet effective manner but also provide them with retention characteristics which eliminate the problem above described. It provides for guide units in the nature of dies and bushings having segments of a charactor that their simple installation effects an essentially permanently seal therebetween. Thus, guide units as provided by the invention have the advantageous features of the split unit but once applied assume the advantageous physical characteristics of the integral unit.

A primary object of the present invention is to provide improvements in split guide units in the nature of bushings or dies rendering them economical to fabricate, more efiicient and satisfactory in use and adaptable to a wide variety of applications.

A further object of the invention is to provide a split or segmented guide unit in the nature of a die or bushing which can be simply installed in a manner to effect a permanent seal between its various segments and to the structure to which it mounts.

Another object of the invention is to provide a device in the nature of a split die, bushing or the like, the components of which are so designed that they may be easily assembled, and in a manner to render them highly resistant to shifting under applied loads.

A further object of the invention is to provide a versatile guide unit possessing the advantageous structural features, the inherent meritorious characteristics and the mode of operation herein mentioned.

With the above and other incidental objects in view as will more fully appear in the specification, the invention intended to be protected by Letters Patent consists of the features of construction, the parts and combinaions thereof, and the mode of operation as hereinafter described or illustrated in the accompanying drawings, or their equivalents.

Referring to the accompanying drawing wherein is shown one but obviously not necessarily the only form of embodiment of the invention,

FIG. 1 is a plan view of the entrance end of split guide unit in accordance with the invention as applied to a stripper plate shown in fragmentary form; and

FIG. 2 is an elevation view of the apparatus illustrated in FIG. 1.

Like parts are indicated by similar characters of reference throughout the several views.

This invention can be best described with particular reference to the accompanying drawings. The guide de- 3,166,359 Patented Jan. 19, 1965 vice substantially as shown, can be selectivelyemployed as a bushing or an extrusion or drawing die. It consists of identical mating halves 2 and 3 having abutting planar surfaces 4. Centrally and longitudinally of the surfaces 4 are portions formed to define mating depressions 5. The outermost peripheral surfaces 6 and 7 of the respective halves 2 and 3 are formed to mutually provide the guide 1 with an outer configuration which is smoothly arcuate in cross-section, as shown in the drawings. In the mating of the halves 2 and 3 the depressions 5 mutually form a guide passage 8 therebetween.

Viewing FIG. 1 of the drawings, it may be observed that with the halves 2 and 3 in assembled relation, their surfaces 4 coextensively abut to define a common plane. A plane perpendicular to this common plane at the center of the surfaces 4 extends through what may be considered the respective apex portions 10 of the surfaces 6 and 7. The curve of each of the surfaces 6 and 7, in cross-section, is identical to either side of its apex portions 10 and to its respective extremities 9 which terminate at opposite edges of the surfaces 4.

The device as illustrated, including the halves 2 and 3, is made for press fit in a plug fit nominal size round hole. The form of the cross-section of its segments is established with reference to the hole considering the unit 1 as a whole, the transverse dimension of the surfaces 4 extending between terminal portions 9 of surfaces 6 or 7 as an X dimension and that of a line perpendicular to the surfaces 4 at their centers and extending between the apex portions 10 of the surfaces 6 and 7 as a Y dimension. As provided by the invention, the X dimension is undersize with reference to the hole and the Y dimensionis oversize. For example, in a preferred embodiment the X dimension could be .0006 inch undersize and the Y dimension from .0002 to .0004 oversize.

Thus, in the example shown, the mating halves Z and 3 establish a cross-section of a bushing or die for application in a round hole, which bushing is out of round in the manner prescribed. On application of this guide unit in the appropriate hole, which may be in any suitable holder such as a stripper plate 11, as shown in the drawings, one half 2 can be easily slipped into the hole while the other half 3 can be easily started by tipping it slightiy as it is introduced into the hole to place the surfaces 4 of the respective halves in directly opposed relatively abutting relation. Any normal press fit procedure may then be employed to complete the insertion of the second half. The respective configuration of the halves insure that when they are completely assembled so their surfaces 4 mate, a relative unbalanced condition results.

whereby the' mass of the holder or stripper plate is stressed to apply a pressure across the split between the segments at the surfaces 4. In effect there is thus provided an essentially permanent seal between the surfaces 4. In use, the split guide so provided will be highly resistant to opening at the plane of separation between its segments, being firmly lodged in a most simple and effective fashion.

It may be seen the character of the invention embodiment is such to eliminate the problem of press fitting both halves at once as is normally entailed in the employment of a conventional split guide. Thus, the present invention makes the use and application of split guide units more economical and desirable and the end product is such to effectively resist forces which would normally tend to separate its segments.

While the device above illustrated is intended for application by means of a press fit to a plug fit nominal size round hole, the invention concepts can be just as readily applied to holes of symmetrical contour which are other than round in cross-section.

Accordingly, it may be seen that the invention provides a simple but highly important advance in the art enabling a split guide which may be easily installed in a simple manner to establish its segments in a relatively sealed contact which resists separation. Its products enable a substantial expansion of the application and use of split bushings, dies andother guide units of similar nature. 7

From the above description it will be apparent that there is thus provided a device of the character described possessing the particular features of advantage before enumerated as desirable, but which obviously is susceptible of modification in its form, proportions, detail construction and arrangement of parts without departing from the principle involved or sacrificing any of its advantages.

While in order to comply with the statue the invention has been described in language more or less specific as to structural features, it is to be understood that the invention is not limited to the specific features shown, but that the means and construction herein disclosed comprise but one of several modes of putting the invention into effect, and the invention is therefore claimed in any of its forms or modifications within the legitimate and valid scope of the appended claims.

Having thus described my. invention, I claim:

1. In combination, a device having means defining a through aperture and a guide unit confined within said through aperture; characterized by said guide unit consisting of sections defining a plane of separation therebetween and having means provided substantially at right angles to said plane of separation so dimensioned in reference to the cross section of said aperture and arranged on confinement thereof within said means defining said through aperture to produce a stress on said means defining said through aperture and a resultant pressure on said guide unit which is at a maximum substantially at right angles to said plane or separation. 2. In combination, a device having means defining a through aperture and a guide bushing confined within said through aperture, said guide bushing, including a' pair of half sections each having opposing sides, one fiat and one continuously curved, the fiat sides of said sections form ing faces in mating contacting relation to one another and the curved sides of said sections forming continuations of one another to define the bushing periphery; characterized in that said sections form an out of round periphery defining different bushing diameters at right angles to one another, one diameter exceeding a normal press fit allowance and the other being less than such allowance with respect to said aperture.

3. A guide bushing according to claim 2, further characterized in that said one diameter is perpendicular to the flat sides of said sections whereby upon installation of the bushing to stress said sections in a direction to close said faces tightly upon one another.

4-. In combination, a device having means defining a through aperture and a guide bushing confined within said through aperture, said guide bushing including a pair of half sections each having opposing sides, one flat and one continuously curved, the flat sides of said sections forming faces in mating contacting relation to one another and the curved sides of said sections forming continuations of one another to define the bushing periphery, characterized in that the curved face of each of said sections is formed on a changing radius whereby said sections define an out of round periphery and said through aperture is formed in a manner that on receipt of said sections, said means defining said through aperture is stressed thereby to produce a pressured containment of said sections to form and fix said guide bushing relative thereto. 7

5. A guide bushing according to claim 4, wherein the radius of the curved side of each of said sections achieves a maximum at a point intermediate the ends of said curved side with the points of maximum radius on mating sections being diametrically opposed to one another.

6. A guide bushing according to claim 5, characterized in that said points of maximum radius occupy a plane at right angles to the plane of mating contact of said flat sections.

7. In combination, a device having means defining a through aperture and a guide unit confined within said through aperture; characterized .by said guide unit consisting of segments arranged in mutually contacting relation to define a guide passage, one of the outer peripheral configuration generally defined by said segments and the peripheral configuration of said through aperture being round and the other out of round and said configurations being relatively dimensioned whereby the assembly of said segments within said through aperture produces a stress on said means defining said through aperture and a resultant pressure which maintains a fixed relation of said segments.

References Cited in the file of this patent UNITED STATES PATENTS 510,990 Pilkington Dec. 19, 1893 2,006,845 Smith July 2, 1935 2,170,718 Humphries Aug. 22, 1939 2,270,500 Brill Jan. 20, 1942 2,407,928 Herreshofi Sept. 17, 1946 

1. IN COMBINATION, A DEVICE HAING MEANS DEFINING A THROUGH APERTURE AND A GUIDE UNIT CONFINED WITHIN SAID THROUGH APERTURE; CHARACTERIZED BY SAID GUIDE UNIT CONSISING OF SECTIONS DEFINING A PLANE OF SEPARATION THEREBETWEEN AND HAVING MEANS PROVIDED SUBSTANTIALLY AT RIGHT ANGLES TO SAID PLANE OF SEPARATION SO DIMENSIONED IN REFERENCE TO THE CROSS SECTION OF SAID APERTURE AND ARRANGED ON CONFINEMENT THEREOF WITHIN SAID MEANS DEFINING SAID THROUGH APERTURE TO PRODUCE A STRESS ON SAID MEANS DEFINING SAID THROUGH APERTURE AND A RESULTANT PRESSURE ON SAID GUIDE UNIT WHICH IS AT A MAXIMUM SUBSTANTIALLY AT RIGHT ANGLES TO SAID PLANE OR SEPARATION. 